Electric furnace.



P. L. T. HB'ROULT.

ELECTRIC FURNAGE.

APPLIOATION FILED MAY 3. 1907.

913,888. l y, Patented Mar.2,19o9.

zsHBETs-SHEET 1.

, WWW/lm .fin/111mm A I INVENTR W1TNE55ES JMW T HEROULT.

FURNAGE.

ED M

ELECTRIC APPLICATION PIL AY 3. 1907.

Patent-,ea Mar. 2, 1909. 2 SHEETS-SHEET' 2.

INVENTOR i PNA.l 91335888.4

. To it concern; l

. thefollowing is a specification.

ELECTRIC ,FUnNaom .-Be it lmown that I, PAUL Louis ToUs- 'sA1N'r; HRoU'L'r, acitizenof the Republic of France,.residing' at La Praz, Savoie, France, have invented certain new and useful Im provements in Electric Furnaces, of which This invention aims to provide for the va? rying of the arc gap in arc furnaces, or of the degree of contact in incandescent furnaces, so-as to controlin eithercase the current passing ,through the furnace with the use of an electrode'which is fixed, at least' during 'operatie]'1.1` This xity of; the electrode serves to 'eliminate various difficulties encountered `previous t es of furnace in which vtheielectrode 'has ad toibe adjusted through.s Lwater-cooled stuflng-box, 'and in *which the. censtruction of-[this -stufllgbox .f 'lesscomplicated .and also ofthe connections and supports :of the-outer Iend ofitheelectrode rwere-fmore1er' present-invention the face vof 'the charge Wlnchis :opposite the end ofthe electrodeis moved toward and from th`e electrode, being at the same time re tamed in aposition parallel to itself. This movement of the charge is adapted to vary According to 'my the resistance and consequently the Vcurrent by shortenin the .gap in an arc, furnace or by varying 4the egree of contact with the electrode in an incandescent furnace. The face of` the ,charge 4is preferably maintained parallel to itself by being fed-Lon aninclination -corres onding with the natural slope of thel material, 4.thissalope being-approximatel the samefor .alldry substances which mig' t be bengautomaticall .usedin' electric-.furnaces. Such a slope or' inclination maintains 'itself always at about the. same angle', .depressions Which occur Vtherem*duri-ng theo eration fof the furnace ed up.

Yarioush'other eatures `r'oi improvement are 1 1eferned?t oin.detail hereinafter.

The -accnxnpanying-- drawings illustrate embodimentsnftheinvention. Figure l isa longitudinal section approxi- Y mately on the line l-lvof Fig.'2. Fig. 2 1s a :horizontal section approximatelyjon the line` 1 in the operation of an incandescent furnace.'

eferrmgitoethe embodiment of the invenff,

tnnillustratedfFigs. 1 and 2, the furnace 'Specification of Letterslatent.

Application med nay s, 1907. lserial' No. 371,691.

PATENT onirica.

PAUL 1.,"1, `nnnourfig forf- LA- PnaafFRANCE,'As-SIGNOR To sooIE'rE Jim1-Annunciataf-FnANcAIsE,

ELECTRO- or-Fnoens; ISERE, FRANCE;

Patented March I2, 1909.

stationary terminal and from which the current 1s carried away in any suitable manner,

and side Walls B and overhanging Walls C of clay or other nonconducting material. The material is fed in to the furnace by Way of a shaft D of less diameter than the body of the furnace in proportion to the length of the overhanging Walls C. The charge E, which may, forexam le, be of iron ore and coke, `is in the form o a vertical or approXimatel vertical column Which spreads out below the --overhanging Walls C, and maintains a slope F Which-1s approximately 42 degrees. The

.overhang of the Walls C is made just suil- .cientv to .provide a triangular space G which Will accommodate the electrode .and slide hereinafter referred to. 'llhev corner of the overhanging Walls C vis preferably provided with acirculating ipe H'for. coolinggit, so as tomalre it 'dura le.-` Into lthe triangular s ace Gris extended the end ,Of-one orm'ore e ectrodes J, and 'the endof .the electrode is tapered oi so as to be parallel to the slope F, or will taper itself in .a short time. The electrode may pass through a bushing K, cooled or not .as desired, and which may serve as a contacter a cap L, With the usual connections to thecable M, may be provided, and provision may also be made for adjusting the electrode, as by means of the screw N indicated'in Fig. A1. Y

The movement of the charge is eected by means of afslide vO which is adapted to be Withdrawn under the ed e of the overhanging Wall C, as shown in fu l lines, or to be projected sufficiently to move the slope F back to. the dotted line F. This slide, for example, maybe -a flat plate (Water cooled, if necessary) of a sufficlent breadth to cover 4the electrode and protect it from the charge at the sides, and may be rovided with a screw P at the outer end or manipulating it.` A bushing Q may be provided Whereit passes' through the Wall of the furnace. ,his arrangement is adapted for furnaces lutilizing either a continuous or an alternating current, and for either a single pair of terminals or any multiple arran ement. 4For example, in Fig. y2 it 1s indicate as ap'- plied toa threaphase system, thegenerators thence through the arc and through the more or less resistant solid-charge E to the liquefied portion S of the charge which collects at the bottom of the furnace, andl descent furnace; the term incandescent being applied only to the type of furnace which operates entirely on the incandescent principle without the use of any definite arcs. instead of arranging the system with a star connection as shown, the bottoni connection of theV furnace may be suppressed and the electrodes arranged in a triangular connection, in which case it will operate as in lother well known three-phase furnaces, the

current passingl from one electrode to the others.

By adjusting the electrode J inwardly until it makes contact with the charge, the furnace will operate as an incandescent fury nace exclusively. The depth and other diheat the charge.

mensions of the furnace may be so designed as to adapt it for use either as an incandescent or as an arc furnace.

For arc furnaces the end of the electrode should be faced off apprommately parallel to the charge. direction the electrode itself lies. For example, it may be arranged vertically, as shown in full lines at J in Fig. 3, or obliquely, as shown in dotted lines at J2. Likewise the means for shifting the charge toward and from the electrode may be differently arranged. For example, a vertical'slide O may be used, as in Fig. 3, l against the inner face ofthe shaft D amine-ll justable vertically and held in position as by a screw T.

For an incandescent furnace the electrode J", Fig. 4, may be arranged in such a osition as to be always in contact with the c arge E over a greater or less portion of the face of the electrode, thus increasing or diminishing the resistance without varying the character of the furnace. The same means may be used in shifting the charge as are proposed in connection with furnaces of the arc type.

Furnaces of this type have the great advantage that they may be open at the top. The escapin gases may be freely burned, and the com ustion may be utilized to re- For example, the shaft D may be extended upwardl sufficiently to form a chimney through w ich pass one or more tubes U carrying the charge and emptying into the body E of the char e.

i, Supposing the smelting of iron ore to e under` consideration, the lower ends of the tubes U may be placed at approx'mately the polnt where the rising car on monoxid has But it is immaterial 1n What I fullest extent possible, and has. been so far converted into carbon dioxid that the mixture may be said to be Vsaturated with the latter, so that if the gases passed any further through the charge there would be a burning of the coke which would counterbalance or overbalance the reduction of the ore. At this point the escaping gases may be burned, being rich in carbon monoxid, and the heat of combustion will be transmitted through the tubes U or by any other means to the charge therein, thus lessening the work of the current by an amount which would otherwise be necessary for supplying a large number of heat units.

ln the ordinary furnace with a vertical electrode about which the charge passes, there is at the lower corners of the electrode a forced contact with the charge, of which particles of molten iron absorb portions of the electrode so as to eat away its end. By the passing of the current to the inclined face ofthe charge as shown, an contact of the charge with the electro e may be avoided, and this eating away of the end of the electrode may be eliminated. Again, with the ordinary vertical electrode there is formed immediately about the arc carbon monoxid, and a slight distance .above the arc carbon dioxid, which attacks the sides of the electrode, (especially on-account of its temperature being higher than that of the adjacent charge),.and burns it, so that the end of the electrode is reduced to the shape of a knob connected by a smaller neck with the upper part of the electrode. But by feeding the charge on an incline as shown, the end of the electrode is in a substantially permanently closed space and is not exposed to any of the gases except the carbon monoxid formed immediately about it and which is not oxidizing. These advantages are irres ective of the iixity or movability of the e ectrode.

accomplished the reduction of the ore to the l do not claim inthis application the procp ess above described, the same being claimed in a divisional application No. 462,430, filed November 13, 1908. y

Though I have described with great'particularity of detail certain embodiments of my invention, yet it is not to be understood therefrom that the invention is restricted to the particular embodiments disclosed. Various modifications may be made by those skilled in the art without departure from the invention.

What4 I claim is f 1..An electric furnace including in combination a stationary terminal, an electrode, and means for shifting ay face of the charge toward and from said electrode.

l 2. An electric furnace including in combination means for maintaining the charge with an inclined face, an electrode opposite said inclined face, and means for shifting the inclined face of the charge toward and from said electrode.

,shaft D through which the charge enters,

charge to a point Within said shaft, whereby 3.. An electric furnace having side Walls B for maintaining a column of the charge, an overhanging Wall C, a shaft D above said overhanging Wall and through which the charge is fed, and an electrode beneath said overhanging Wall, said parts being proportioned/and located to permit the removal of the electrode out of contact with the charge.

4. An electric furnace having an electrode with its end in an inclosed space so as to be exposed to no gases eXce t those formed immediately about it, and having a shaft D communicating with the upper part of said inclosed space.

5. An electric furnace having an open and having tubes U for conducting the the burning of the gases above such point may heat the charge "as it passes through the tubes U Without direct contact of the gases With the charge, and having an electrode entering the furnace at the side.

6. An electric furnace having an over-v hanging Wall G, an .electrode beneath said overhanging Wall, and a slide adapted to engage the material passing the edge of said overhanging Wall and to shift the face of such material toward and from the` electrode.

7. An electric furnace including in combination an electrode, and means overlying the same and controlling the proximity or degree of contact of the charge with the electrode.

In Witness whereof, I have hereunto signed my name in the presenceof two subscribing Witnesses.

W itnesses:

DOMINGO A. UsrNA, THEonoRE T. SNELL.

V PAUL L. rr. HROULT.v 

